[llvm] r326900 - Revert rL326898: "Teach CorrelatedValuePropagation to reduce the width of udiv/urem instructions."
Justin Lebar via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 7 08:05:44 PST 2018
Author: jlebar
Date: Wed Mar 7 08:05:43 2018
New Revision: 326900
URL: http://llvm.org/viewvc/llvm-project?rev=326900&view=rev
Log:
Revert rL326898: "Teach CorrelatedValuePropagation to reduce the width of udiv/urem instructions."
Breaks bootstrap builds: clang built with this patch asserts while
building MCDwarf.cpp: Assertion `castIsValid(op, S, Ty) && "Invalid
cast!"' failed.
Removed:
llvm/trunk/test/Transforms/CorrelatedValuePropagation/udiv.ll
llvm/trunk/test/Transforms/CorrelatedValuePropagation/urem.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp?rev=326900&r1=326899&r2=326900&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/CorrelatedValuePropagation.cpp Wed Mar 7 08:05:43 2018
@@ -58,7 +58,6 @@ STATISTIC(NumCmps, "Number of compa
STATISTIC(NumReturns, "Number of return values propagated");
STATISTIC(NumDeadCases, "Number of switch cases removed");
STATISTIC(NumSDivs, "Number of sdiv converted to udiv");
-STATISTIC(NumUDivs, "Number of udivs whose width was decreased");
STATISTIC(NumAShrs, "Number of ashr converted to lshr");
STATISTIC(NumSRems, "Number of srem converted to urem");
STATISTIC(NumOverflows, "Number of overflow checks removed");
@@ -433,46 +432,6 @@ static bool hasPositiveOperands(BinaryOp
return true;
}
-/// Try to shrink a udiv/urem's width down to the smallest power of two that's
-/// sufficient to contain its operands.
-static bool processUDivOrURem(BinaryOperator *Instr, LazyValueInfo *LVI) {
- assert(Instr->getOpcode() == Instruction::UDiv ||
- Instr->getOpcode() == Instruction::URem);
- if (Instr->getType()->isVectorTy())
- return false;
-
- // Find the smallest power of two bitwidth that's sufficient to hold Instr's
- // operands.
- auto OrigWidth = Instr->getType()->getIntegerBitWidth();
- ConstantRange OperandRange(OrigWidth, /*isFullset=*/false);
- for (Value *Operand : Instr->operands()) {
- OperandRange = OperandRange.unionWith(
- LVI->getConstantRange(Operand, Instr->getParent()));
- }
- // Don't shrink below 8 bits wide.
- unsigned NewWidth = std::max<unsigned>(
- PowerOf2Ceil(OperandRange.getUnsignedMax().getActiveBits()), 8);
- if (NewWidth == OrigWidth)
- return false;
-
- ++NumUDivs;
- auto *TruncTy = Type::getIntNTy(Instr->getContext(), NewWidth);
- auto *LHS = CastInst::Create(Instruction::Trunc, Instr->getOperand(0), TruncTy,
- Instr->getName() + ".lhs.trunc", Instr);
- auto *RHS = CastInst::Create(Instruction::Trunc, Instr->getOperand(1), TruncTy,
- Instr->getName() + ".rhs.trunc", Instr);
- auto *BO =
- BinaryOperator::Create(Instr->getOpcode(), LHS, RHS, Instr->getName(), Instr);
- auto *Zext = CastInst::Create(Instruction::ZExt, BO, Instr->getType(),
- Instr->getName() + ".zext", Instr);
- if (BO->getOpcode() == Instruction::UDiv)
- BO->setIsExact(Instr->isExact());
-
- Instr->replaceAllUsesWith(Zext);
- Instr->eraseFromParent();
- return true;
-}
-
static bool processSRem(BinaryOperator *SDI, LazyValueInfo *LVI) {
if (SDI->getType()->isVectorTy() || !hasPositiveOperands(SDI, LVI))
return false;
@@ -482,10 +441,6 @@ static bool processSRem(BinaryOperator *
SDI->getName(), SDI);
SDI->replaceAllUsesWith(BO);
SDI->eraseFromParent();
-
- // Try to process our new urem.
- processUDivOrURem(BO, LVI);
-
return true;
}
@@ -505,9 +460,6 @@ static bool processSDiv(BinaryOperator *
SDI->replaceAllUsesWith(BO);
SDI->eraseFromParent();
- // Try to simplify our new udiv.
- processUDivOrURem(BO, LVI);
-
return true;
}
@@ -643,10 +595,6 @@ static bool runImpl(Function &F, LazyVal
case Instruction::SDiv:
BBChanged |= processSDiv(cast<BinaryOperator>(II), LVI);
break;
- case Instruction::UDiv:
- case Instruction::URem:
- BBChanged |= processUDivOrURem(cast<BinaryOperator>(II), LVI);
- break;
case Instruction::AShr:
BBChanged |= processAShr(cast<BinaryOperator>(II), LVI);
break;
Removed: llvm/trunk/test/Transforms/CorrelatedValuePropagation/udiv.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CorrelatedValuePropagation/udiv.ll?rev=326899&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/CorrelatedValuePropagation/udiv.ll (original)
+++ llvm/trunk/test/Transforms/CorrelatedValuePropagation/udiv.ll (removed)
@@ -1,95 +0,0 @@
-; RUN: opt < %s -correlated-propagation -S | FileCheck %s
-
-; CHECK-LABEL: @test_nop
-define void @test_nop(i32 %n) {
-; CHECK udiv i32 %n, 100
- %div = udiv i32 %n, 100
- ret void
-}
-
-; CHECK-LABEL: @test1(
-define void @test1(i32 %n) {
-entry:
- %cmp = icmp ule i32 %n, 65535
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: udiv i16
- %div = udiv i32 %n, 100
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test2(
-define void @test2(i32 %n) {
-entry:
- %cmp = icmp ule i32 %n, 65536
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: udiv i32 %n, 100
- %div = udiv i32 %n, 100
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test3(
-define void @test3(i32 %m, i32 %n) {
-entry:
- %cmp1 = icmp ult i32 %m, 65535
- %cmp2 = icmp ult i32 %n, 65535
- %cmp = and i1 %cmp1, %cmp2
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: udiv i16
- %div = udiv i32 %m, %n
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test4(
-define void @test4(i32 %m, i32 %n) {
-entry:
- %cmp1 = icmp ult i32 %m, 65535
- %cmp2 = icmp ule i32 %n, 65536
- %cmp = and i1 %cmp1, %cmp2
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: udiv i32 %m, %n
- %div = udiv i32 %m, %n
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test5
-define void @test5(i32 %n) {
- %trunc = and i32 %n, 65535
- ; CHECK: udiv i16
- %div = udiv i32 %trunc, 42
- ret void
-}
-
-; CHECK-LABEL: @test6
-define void @test6(i32 %n) {
-entry:
- %cmp = icmp ule i32 %n, 255
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: udiv i8
- %div = sdiv i32 %n, 100
- br label %exit
-
-exit:
- ret void
-}
Removed: llvm/trunk/test/Transforms/CorrelatedValuePropagation/urem.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/CorrelatedValuePropagation/urem.ll?rev=326899&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/CorrelatedValuePropagation/urem.ll (original)
+++ llvm/trunk/test/Transforms/CorrelatedValuePropagation/urem.ll (removed)
@@ -1,95 +0,0 @@
-; RUN: opt < %s -correlated-propagation -S | FileCheck %s
-
-; CHECK-LABEL: @test_nop
-define void @test_nop(i32 %n) {
-; CHECK udiv i32 %n, 100
- %div = udiv i32 %n, 100
- ret void
-}
-
-; CHECK-LABEL: @test1(
-define void @test1(i32 %n) {
-entry:
- %cmp = icmp ule i32 %n, 65535
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: urem i16
- %div = urem i32 %n, 100
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test2(
-define void @test2(i32 %n) {
-entry:
- %cmp = icmp ule i32 %n, 65536
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: urem i32 %n, 100
- %div = urem i32 %n, 100
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test3(
-define void @test3(i32 %m, i32 %n) {
-entry:
- %cmp1 = icmp ult i32 %m, 65535
- %cmp2 = icmp ult i32 %n, 65535
- %cmp = and i1 %cmp1, %cmp2
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: urem i16
- %div = urem i32 %m, %n
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test4(
-define void @test4(i32 %m, i32 %n) {
-entry:
- %cmp1 = icmp ult i32 %m, 65535
- %cmp2 = icmp ule i32 %n, 65536
- %cmp = and i1 %cmp1, %cmp2
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: urem i32 %m, %n
- %div = urem i32 %m, %n
- br label %exit
-
-exit:
- ret void
-}
-
-; CHECK-LABEL: @test5
-define void @test5(i32 %n) {
- %trunc = and i32 %n, 63
- ; CHECK: urem i8
- %div = urem i32 %trunc, 42
- ret void
-}
-
-; CHECK-LABEL: @test6
-define void @test6(i32 %n) {
-entry:
- %cmp = icmp ule i32 %n, 255
- br i1 %cmp, label %bb, label %exit
-
-bb:
-; CHECK: urem i8
- %div = srem i32 %n, 100
- br label %exit
-
-exit:
- ret void
-}
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